A timing chain drive device is provided with chain guides which are brought into contact with middle portions of a timing chain endlessly provided around drive and driven sprockets and running at high speed, and is configured to press at least one of the chain guides against the timing chain in the direction substantially perpendicular to the running direction of the timing chain, and to thereby apply tension to the timing chain so as to prevent the timing chain from being slacked.
The chain guide is configured to guide the chain while being in contact with the chain, and hence sliding resistance is generated due to friction between the chain guide and the timing chain, causing a problem of an increased noise and mechanical loss.
Known techniques for suppressing the noise and mechanical loss of the chain guide include those described in Patent Literature 1 and Patent Literature 2. The chain guides described in Patent Literature 1 and Patent Literature 2 are formed in a curved shape along the running direction of the timing chain, in which rollers are arranged at a sliding-surface portion which is brought into contact with the timing chain, and the rollers are rolled by being pressed against the timing chain running at high speed, and thereby the sliding resistance is reduced.